慢性轻中度碘过量对碘缺乏大鼠及非碘缺乏大鼠甲状腺抗氧化能力的影响  

Effect of chronic mild and moderate iodine excess on thyroid anti-oxidative ability of iodine dificiency and non-iodine dificiency Wistar rats

作　　者：张诺[1] 佟雅洁[1] 单忠艳[1] 滕卫平[1] 

机构地区：[1]中国医科大学附属第一医院内分泌科

出　　处：《中华医学杂志》2006年第18期1274-1278,共5页National Medical Journal of China

基　　金：国家自然科学基金资助项目(30240013)

摘　　要：目的动态观察慢性轻中度碘过量对碘缺乏及非碘缺乏Wistar大鼠甲状腺氧化损伤和抗氧化能力的影响。方法4周龄Wistar大鼠饲以低碘饲料3个月,复制出低碘甲状腺肿模型后随机分为3组:低碘对照组(IDC)、补碘Ⅰ组(ISⅠ)和补碘Ⅱ组(ISⅡ)。各组分别饲以双蒸水、含碘100μg/L和330μg/L的碘酸钾水。另有4周龄Wistar大鼠饲以普通饲料3个月,随机分为3组:正常对照组(NC)、高碘I组(IEⅠ)和高碘Ⅱ组(IEⅡ)。各组分别饲以双蒸水、含碘300μg/L和660μg/L的碘酸钾水。在给予处理因素的1、2、4、8、24周时处死大鼠。采用生化方法测定大鼠甲状腺内谷胱甘肽过氧化酶(GSH PX)和超氧化物歧化酶(SOD)的活力,以及丙二醛(MDA)及过氧化氢(H2O2)的含量。结果与IDC组比较,ISⅠ组和ISⅡ组甲状腺内MDA及H2O2含量在1、2、4、8及24周时均明显下降(P<0.05、P<0.01或P<0.001);补碘后ISⅠ组和ISⅡ组甲状腺GSH PX活力均呈现明显下降趋势,分别在4周和2周后明显低于同期IDC组(P<0.001或P<0.05),GSH PX在4周和24周还低于同期NC组(P<0.001、P<0.01或P<0.05)。ISⅠ组和ISⅡ组甲状腺SOD活力也呈现逐渐下降趋势,在8周后明显低于同期IDC组(P<0.001或P<0.05)。与NC组相比,24周时IEI组和IEⅡ组甲状腺内GSH PX活力明显下降(P<0.01)。结论碘缺乏Wistar大鼠补充100μg/L和330μg/L浓度碘后甲状腺氧化损伤程度减轻,但同时存在甲状腺抗氧化防御能力下降。非碘缺乏Wistar大鼠长期补充300μg/L和660μg/L浓度碘同样使甲状腺抗氧化防御能力降低,甲状腺面临氧化损伤的威胁。Objective To investigate the effects of chronic mild and moderate iodine excess on thyroid oxidative injury and anti-oxidative ability of iodine deficiency and non-iodine deficiency Wistar rats. Methods Four-week-old Wistar rats were fed with iodine deficient diet for three months to make iodine deficient goiter models, then divided randomly into three groups： iodine deficient control group （ Group IDC） fed with double distilled water, iodine-supplement group Ⅰ （Group IS Ⅰ ） fed with potassium iodate solutions with the iodine concentrations of 100 μg/L, and iodine-supplement group Ⅱ （ Group IS Ⅱ ）, fed with potassium iodate solution with the iodine concentrations of 330 μg/L. Another four-week-old Wistar rats were fed with normal diet for three months, and then divided randomly into three groups： normal control group （NC） fed with double distilled water, iodine-excess group Ⅰ （IE Ⅰ ） fed with potassium iodate solution with the iodine concentration of 300 μg/L, and iodine-excess group Ⅱ （Group IE Ⅱ ）, fed with potassium iodate solution with the iodine concentration of 660 μg/L. 1,2, 4, 8, and 24 weeks after treatment samples of urine were collected to detect the median urine iodine （ MUI）, samples of plasma were collected from the hearts of 8 - 14 rats from each group and then rats were killed. Their thyroid glands were taken out to measure the wet weight and made into homogenate. Biochemical method was used to measure the activities of glutathion2-peroxidae （GSH-Px ） and superoxide dismutase （SOD） as well as the contents of malonyldialdehyde （MDA） and H202 in the homogenates of thyroid glands. Results The GSH-Px activity 2 weeks after treatment of Group IS Ⅱ was significantly lower than that of Group IDC （ P 〈 0.05 ）, and the GSH-Px activity 4 weeks after treatment of Group IS Ⅰ was significantly lower than that of Group IDC （ P 〈 0.001）. The activities of GSH-Px 4, 8, and 24 weeks after treatment of Groups IS Ⅰ and IS Ⅱ were all

关 键 词：碘 甲状腺 创伤和损伤 氧化性应激 

分 类 号：R581[医药卫生—内分泌]